my brother in law has a 1972 1.7 with fi the rpms stay up when you let off the gas the ped is not boun up . if I rev it from the motor it stays reved and slowly gose down. any ideals? thanks doug h

I would look at the throttle return spring, it may be weak/stretched.

Possibly "dirt" causing some resistance to the throttle closing easily, so it returns slowly.

Where the throttle cable comes out the firewall maybe be a problem. My throttle cable was sticking too because there is a metal shelve and then the cable. My cable had a sharp angle coming out the metal shelve. I made sure that excess cable can be pushed down through the engine tin to the firewall. To help prevent the sharp angle, I got an old fuel line about two inches and split it and placed it over the shelve and cable then zip tied it. Has not gotten stuck since.

yeah - disconnect throttle cable and see if engine responds the same by hand throttling.

cables do fray over time.

if still slow to come back after disconnecting the cable, check for vacuum leaks